Human memory is a polygenic cognitive trait. Heritability estimates of approximately fifty percent (50%) suggest that naturally occurring genetic variability has an important impact on this fundamental brain function. (G. E. McClearn et al., Science 276, 1560 (1997)). Recent candidate-gene association studies have successfully identified some genetic variations with significant impact on human memory capacity and human memory performance. (D. J. de Quervain et al., Nat. Neurosci. 6, 1141 (2003); A. Papassotiropoulos et al. Hum. Mol. Genet. 14, 2241 (2005)). However, the success of such hypothesis-driven studies strongly depends upon pre-existing information, which limits their potential to identify novel genes and molecular pathways. (N. J. Schork, Adv. Genet. 42, 299 (2001); J. R. Kelsoe, Int. Rev. Psychiatry 16, 294 (2004)). To date, an unbiased hypothesis-free search of the whole genome for human memory-controlling genes has not been performed. Therefore, there is a clear unmet need in the art to identify genes and genetic variations associated with human memory.